Fuel cells, especially hydrogen fuel cells, have received increasing interest as on-demand, portable power sources. In particular, there has been an increased interest in leveraging fuel cell technology to power portable consumer devices, especially as battery replacements. Fuel cells are exceptionally interesting as battery replacements because not only do fuel cells present fewer environmental concerns than batteries, but they have an exceptionally longer lifespan, as fuel cells produce electricity only when needed. Thus, fuel cells can be theoretically used for an unlimited period of time as long as the fuel supply, which provides the fuel that the fuel cell consumes to generate electricity, is periodically replaced. This fuel supply can be pure-fuel storage, such as a tank of hydrogen gas, or it can be a fuel generator that utilizes chemical precursors (such as a sodium borohydride slurry or dry sodium borohydride and water) to generate the fuel. The latter option is often preferred due to the higher fuel stability.
In order for the fuel cell to power portable electronics on-demand, both the fuel cell and the fuel supply must be portable and preferably, easily incorporated into the electronic device itself. While prior art fuel cells can be incorporated easily into a portable package, even incorporated into the product itself, prior art fuel supplies cannot be as easily incorporated into the product due to size limitations. Because the fuel-generating reaction produces corrosive waste products, not only does the fuel supply need to store enough reactant(s) to provide adequate energy density, but it also needs to store the waste products produced by the fuel-generating reactions. Additionally, the storage of the reactant(s) and waste products is preferably accomplished in a fixed volume, as expansion of a fuel supply may damage any device that the fuel supply has been incorporated into.
Thus, there is a need in the fuel supply field to create an improved fuel supply that contains both the requisite reactants and the generated waste products.